Sealing and contacting ultrasound flow meters is a technically demanding and complicated process. Housing openings must be sealed with filigree sealing elements made of the best sealing material. Due the increased use of plastics materials, in which manufacturing tolerances can usually not be ruled out, it is easily possible under specific operating conditions for leaks to occur due to the small dimensions of the sealing elements. Leaks cannot be ruled out even if high-quality sealing materials are selected and time-consuming manual machining takes place.